Historically, the Dibang Valley district got the name after the Dibang River which flows through it and finally debouches into the plains where it meets the Lohit River near Sadiya. It was once the part of the Lohit district and separated in June 1980. On 16th January, 2011 the Dibang Valley district was divided into two parts-the Upper Dibang Valley and the Lower Dibang Valley.

Tine Mena is an Indian mountaineer. She was the first woman from Arunachal Pradesh and the North East India to climb the Mount Everest.

Geographically, the district has a total area of 13,029 sq. km. and occupies the rank 1st in State and 30th in India on the basis of the size. It lies at 28°81'N latitude, 96°15'E longitude and 1968 m altitude. It is surrounded by the China in the North and East, by Lower Dibang Valley District in the South, by China in the East and Upper Siang District in the West. The main rivers that flows through the district are Dibang River, Dri, Mipi, Talon, Embra, Awa are main rivers of the district. It is the largest district in the state of Arunachal Pradesh. In the year of 2019, there were total 70.67% forest area of the total geographical area. The climate of the district remains pleasant almost throughout the year. Most of its rainfall occurs in the monsoon season. The actual rainfall in the district was 2170.7 mm in the year of 2021-22.

Administratively, the district is divided into 5 sub-districts, 1 town and 142 villages. English is its administrative language. The district came into existence in June 1980. It has administrative headquarters located at Anini which is situated at the distance of 562 kms from the State Capital. There is only one legislative assembly constituency in the district is Anini. It is a part of the Arunachal East Lok Sabha constituency.

Demographically, according to the 2011 census, the district has a total number of 1,871 households with a total population of 8,004 comprising 4,414 are males and 3,590 are females which leads it to rank 16th in the state and 640th in India. The density of population of the district is 1 (persons per sq km.). The sex ratio is pegged at 813 (females per 1000 males) while the child ratio stands at 889 (females per 1000 males). The schedule tribe population of the district is recorded as 5,701 including 2,850 are males, and 2,851 are females. The percentage of Schedule Tribe is 0.60%. As per 2011 census the percentage of major religion practiced by the people of this region is Hindu 39.24% of the total population. The population growth rate during the period of 2001-2011 was 10.07% including 2.99% were males and 20.23% were females. According to 2011 census the principal languages in the district are Mishmi and Nepal with 68.73% and 14.19%. In the year 2020 the number of live births in the district was 219 out of which 96 were males and 123 were females. In the same year the number of deaths in the district was 51 out of which 37 were males and 14 were females.

Economically, the district is dependent on agriculture primarily. The peoples of the district also earn from labour, household industry and other industry etc. Jhum cultivation is in practice here. In the year 2021-22 the gross domestic product in the district was Rs. 1,74,873 lakhs at current price and Rs. 1,03,796 lakhs at constant prices in the year 2011-2012. The net domestic product in the district during the period 2021-22 was Rs. 1,60,541 lakh at current price and Rs. 92,920 lakh at constant prices in the year 2011-2012. The Per Capita Income or NDDP, At Factor Cost during the period 2021-22 was Rs. 2,01,400 at current price and Rs. 1,16,569 at constant prices in the year 2011-2012.

Education wise, according to the 2011 census, the district has a literacy rate of 64.1% including 68.07% are males and 59.16% are females. The total population of literate people is 4,436 comprising 2,614 are males and 1,822 are females. The total number of illiterates in the district is 3,568 comprising 1,800 are males and 1,768 are females. The district has Spiritual and theology Colleges, Hotel Management Institutes, Archeology College, Vivekananda Kendriya Vidhyalaya, Jawahar Novodaya Vidhalaya, Kasturba Gandhi Institute of Higher Education and Government Secondary School are some of the main educational institutions in the district.

Shri Rajesh Tacho is the member of the Indian National Congress Party. He became the member of the legislative assembly at the age of 47 Late Khore Tacho is his father.

The district is beautiful with sparkling waterfalls, loitering wild animals, dashing rivers, heavy rainfall, lush green vegetation, moderate climate and chirping birds. Dibang Wild Life Sanctuary, Areas Like Mipi, Alinye (A.L.G.) Anrim valley, Acheso, Dambuen, Mihundo Etc Are Potential Tourist Spots. A number of tourists visit here from the worldwide. The Dibang Wildlife Sanctuary is full of wildlife such as Mishmi takin, red goral, musk deer, red panda, Asiatic black bear, occasional tiger, Gongshan muntjac, Sclater's monal and Blyth's tragopan birds and Mishmi Hills giant flying squirrel. The sanctuary is under the protection of the Department of Environment and Forest of Arunachal Pradesh. Mishmi Hills are located in the centre of Arunachal Pradesh. Mishmi Hills has heavy rainfall. The area has about a big number of plant species, mammal species and bird species. Toiurists can found here tiger, common leopard, clouded leopard, snow leopard, golden cat, jungle cat, marbled cat, the leopard cat, Mishmi takin. Serow, musk deer and the Himalayan black bear.